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Isolation and Characterization of an Enterobacter cloacae Strain That Reduces Hexavalent Chromium under Anaerobic Conditions 总被引:12,自引:6,他引:6 下载免费PDF全文
Pi-Chao Wang Tsukasa Mori Kohya Komori Masanori Sasatsu Kiyoshi Toda Hisao Ohtake 《Applied microbiology》1989,55(7):1665-1669
An Enterobacter cloacae strain (HO1) capable of reducing hexavalent chromium (chromate) was isolated from activated sludge. This bacterium was resistant to chromate under both aerobic and anaerobic conditions. Only the anaerobic culture of the E. cloacae isolate showed chromate reduction. In the anaerobic culture, yellow turned white with chromate and the turbidity increased as the reduction proceeded, suggesting that insoluble chromium hydroxide was formed. E. cloacae is likely to utilize toxic chromate as an electron acceptor anaerobically because (i) the anaerobic growth of E. cloacae HO1 accompanied the decrease of toxic chromate in culture medium, (ii) the chromate-reducing activity was rapidly inhibited by oxygen, and (iii) the reduction occurred more rapidly in glycerol- or acetate-grown cells than in glucose-grown cells. The chromate reduction in E. cloacae HO1 was observed at pH 6.0 to 8.5 (optimum pH, 7.0) and at 10 to 40°C (optimum, 30°C). 相似文献
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Dispersion capabilities of new queens were studied in the two haplometrotic paper wasps Polistes riparius and P. snelleni. New queens were marked on the nests in the late summer and located in the next spring. Dispersion distances greatly varied among queens: although a large part of recovered queens nested in close proximity to their natal sites, some did disperse over 100–300 m. This suggests that queens' emigration from and immigration into the censused areas occurred to a substantial extent. On the whole, these species exhibited a weaker “philopatric” tendency than those so far studied for dispersion distance, and seem to have the potential for a long-distance dispersion. 相似文献
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Shinya Arinaga Nobuya Karimine Masashi Adachi Hiroshi Inoue Shigeru Nanbara Tsukasa Asoh Hiroaki Ueo Tsuyoshi Akiyoshi 《Cancer immunology, immunotherapy : CII》1993,37(4):220-226
We previously found that the ability of peripheral blood mononuclear cells (PBM) of cancer patients to generate lymphokine-activated killer (LAK) cells became remarkably augmented after mitomycin C administration. On the basis of the clinical finding, we designed a treatment regimen comprised of 12 mg/m2 mitomycin C i. v. on day 1 and 700 U/m2 recombinant interleukin-2 (IL-2) i.v. every 12 h from day 4 through day 8. Of 25 patients with advanced carcinoma, 9 had a partial response and 3 had a minor response. Cytotoxic cell function, including natural killer activity, lymphokine-activated killer (LAK) activity, and the ability to generate LAK cells, and lymphocyte subsets in PBM was measured 1 day before and after either the first or second course of this therapy. The relationship between these parameters and the clinical antitumor response to this treatment was examined. Although the cytotoxic activities were significantly augmented after either the first or second treatment course, no positive correlation was observed between the changes in these cytotoxic activities and the clinical response to this therapy, when patients who either showed a partial response or whose disease remission was partial or minor were defined as responders. Further, phenotypic analysis showed a significant increase in CD2+, CD3+ CD4+ and CD4+Leu8– cells after the firs course, and CD25+ cells after either the first or second course of this treatment. The precentages of CD2+ and CD25+ cells were significantly elevated only in responders but not in nonresponders, suggesting the increase in these subsets was related to clinical response. 相似文献
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Matsuo Tsukasa 《Journal of plant research》1983,96(2):127-133
The late-glacial logistic decline of spruce (Picea) populations (the intrinsic growth rate,r in yr?1=?0.0015) was progressively delayed toward cooler sites in Japan; spruce populations expanded asymptotically (r=0.0040?0.0045) in Sakhalin early in the Holocene. Such a time-transgressive range shift in spruce distribution, covering a wide latitudinal range (ca. 35–50°N), implies that the regional temperature rise was not instantaneous, but was rapid, being 0.0015–0.0025 C yr?1 from 13,000 to 10,000 years B.P. Spruce populations increased in response to Neoglacial cooling only at the margin of its distribution (r=0.0036), but then declined logistically 1,000 years B.P. (r=?0.0022). 相似文献
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T Murakami H Ohmori S Gotoh T Tsuda R Ohya S Akiya K Higashi 《Journal of biochemistry》1991,110(1):146-150
Cultured human neuroblastoma (GOTO) cells were induced to differentiate by dibutyryl cyclic AMP (Bt2cAMP) and/or retinoic acid (RA). A combination of Bt2cAMP (1 mM) and RA (1 microM) yielded the most significant networks of neurites after 3 to 4 days, this being associated with the reduction of N-myc mRNA levels. Next, we examined several cellular genes that were possibly linked with changes in N-myc gene expression under these conditions. Among the genes examined, both nucleolin and a major heat-shock protein (hsp70) mRNAs showed changes concomitant with those in N-myc mRNA levels when induced by Bt2cAMP and RA. Dibutyryl cAMP alone induced several short cellular processes and caused a marked decrease in N-myc mRNA within 2 days. RA alone induced a few long and straight neurites along the longitudinal axis of individual cells and a significant decrease in growth rate but showed neither network formation nor a decrease in N-myc gene expression. These results indicate differential effects of Bt2cAMP and RA on the regulatory mechanisms of both cell proliferation and differentiation and also indicate a possible association of expression of N-myc gene with those of hsp70 and nucleolin genes. 相似文献
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